Design optimization of a steering and suspension integrated system based on dynamic constraint analytical target cascading method

Steering system and suspension system are two important subsystems of automobile chassis, and they both influence the vehicle ride comfort, safety, and maneuverability. In order to improve overall performance of chassis system, a hierarchical dynamic constraint analytical target cascading (DCATC) optimization method is proposed and applied to optimize the integrated system. Moreover, DCATC enhances the information exchange between the subsystem and the total system, and improves the convergence and computation speed of the optimization. Based on the dynamic model of the steering and suspension-integrated system, the evaluation indexes of the integrated system are proposed and deduced, which involves steering energy consumption, steering road feel, steering sensitivity, ride comfort, and steering stability. Then the optimization mathematical model of the integrated system is established. The simulation results show that the proposed DCATC can improve the overall performance of the integrated system. The steering energy consumption and steering sensitivity are reduced, and the steering road feel and ride comfort are improved effectively.